Aeroplane.



AERGr-LMsL-- APPLiCATiN [LED MAYS?, mi2. RtNLWED WAH. (M1016, 1,179,978.www@ Apr. 18, 1911;.

2 SHEETS-SHE ZA jUNiTED sTATEs PATENT oEEioE.

ROSCOE P. TIMSON, OF LYNN, AND GEORGE NORMAN ALBREE, OF SWAMPSCOTT,MASSACHUSETTS; .SAID TIMSON ASSiGrNOR TO SAID AIBREE.

AEROPLANE.)

\ k ../Spfgieation of Letters Patent.

Patented Apr. 18, 1916.

Application filed May 31, 1912` Serial o. 700,879.l Renewed March 11,1916. Serial No. 83,689.

To all whom 'it may concern:

Be it known that we, Rose-0E P. TrMsoN and GEORGE NORMAN ALBREE, bothcitizens of the United States, and residents of Lynn and Swamps'cott,respectively, in the county of Essex and State of Massachusetts, haveinvented new and useful Improvements in Aeroplanes, of which the`following 1S a specification. s

-This invention relates to aeroplanes, and has for its objecttheprovision of a planesupported structure characterized -b'y inherentlystable equilibrium, whichl will automatically restore itself to acondition of even balance, whether either longitudinally or laterally,and which is therefore adapted to be safely sustained "I and guidedinthe air provided it is equipped with the usual propulsive machinery.

-In order to -set forth the principles of this invention, the machineherein described ,will be 'considered both in its simple aspect as a andin its completer aspect as a propelled flying machine.

In the drawings hereto annexed, which illustrate an example of theinvention- Figure 1 is a diagram to explain the characteristicv'principle of longitudinal equilichine; Fig.` 4 is a plan supporting yair pressure.

brium; Fig. 2 is a diagram to explain the principle of lateralequilibrium, or automa-l tic self-banking, Fig. 3 is a. front elevationshowing the preferred form of maview of the machine; andlFig. is., aside elefvation of the machine. l il.

Referring to Fig. 1: P represents the supporting planes, H theb.'ckbo'neor framellil aft 0n the line 1 1, T `the tail, and T1 a preponderantweight; these elements being so arranged that the center of grav'Iity ofthe whole structure falls well forward of the center of By Arepeatedexperiment, it has been demonstrated that the center of gravityy cgshould lie about half way between the center of supporting pressure .opand the front edgeof the supporting plane P, provided this 'edge be atright angles to the center line 1-1 of the machine; ThetaillT, whichbalances and controls the flight of the structure is so inclined thatforward movement through the air produces i always a downward airpressure on the tail,

disturbed` ,temporarily at an angle with the plane of support, an anglewhich opens forward, as referred to the direction of movement of themachine. Thus the tendency of the weight lV is to depress the front ofthe machine, while that of the tail is to depress the rear of themachine. The center of pressure cp constitutes the fulcrum to which thedynamic moments of the opposing efforts are referred. Suppose a glidingmachine to be built according to the principles above explained, thetail T set at a fixed angle with the body. B, and therefore with theyplanes P (Fig. 1), and that this glider is simply released in the airat a height-from the'- ground. The tail T then exerts no depressingeffect but the weight lV depresses the head of the glider which fallsdownward and forward; the air pressure on the upper surface of the taildue to the flight increases with the speed of the glider, and depressesthe rear of the machine more and more, until the glider assumes a nearlyhorizontal position, in which it will glide forward and downward in a,straight course. If, instead of being simply released in the air, themachine be given a forward initial impetus, it will ineline upward afterrelease under impulse,

and then incline and glide forward and downward.

It will be clear that if the tail T were set in a greater angle with thecenter line of the glider, its righting effect would be more quicklyasserted'and that also its effect to check the speed of the machinewould be the greater, that with the tail set at a slight angle theeffect wouldbe a swift long glide, while with the tail set at a widerangle the effect would be a slow and short distance glide. It will alsobe clearthat if the tail T were set at a reverse angle, be it ever soslight, its effect would be to lift therear of the machine,supplementing instead of opposing the moment of the weight lV, and that'the machine would turn completely over, and glide, if at all, bottom up.AThis .may easily be tested by launching a glider,

'onstructed as above described, bottom up. It will instantly turn over,and glide to earth right side up.Y

Furtherto illustrate the principle of balance and e'quilibrum of such amachine as is herein illustrated, suppose the weight XV to -betransformed into a motor and propeller Iii vn"ich pro'fortions that withthe motor and the aviator in the machine the static balance ci themachine remains as before. With the tail T set a proper angle, assumethe machine to be in flight at such a` rate that the air, pressing onthe upper surface ot' the tail T holds the machine tilted slightlyupward, so that a whole it travels forward at uI-ichanging elevation.Now suppose the motor speed to be increased increased speed results,`and with it increased pressure on the upper surface of the tail T, whichtilts the h ad of the machine upward until uniprow :s forward and upwardis attaine .Y nould the motor be slowed down, or even stopped. on theother hand, with dmrease in speed of forward motion there mustcomedecrease in downward pressure on the tail T, and then the machine willmove downward at an angle and velocit-y determined by the severalfactors. The effects ot a govern-able tail T will now become apparei'it.Increase ot its angular set, to augment the u: pressure on its surface,will tilt the machine upward, and decreascits rate of progress, andvice-versa. VTo descend to earth, the motor should be stopped thetail-angle increased to a practiille maximum, so as to effect a slow..ownward glide. ln this manner the deibcd rclatioinzhip of the weigh@tail and center of supgiorting pressure on the sup# porting plane incursautomatic balance in the direction ol" liigh't, or in other words,automatically takes care of longitudinal einiilihrium. i

Renaming now to Fig. 2, which shows in dii-:gram the machine coming headon, and tilted sidewise. as it might be by a gust of wind The weight ofthe machine "pulls verticali); dov ward. as at cg, the suppre, l reholds it up, aS ndihv the vertical component 'chili' at the same imethere will be a tendency to,A slide laerallv and downwardly. As the tailT is tilted sidewise. the downward pressure ot' the airwill he exertedat an angle to the vertical, o the line t7), producing a hori- -iontai ffuient si), which` acting at the tail T., sh .vs the tail' ewise, in thedirection el' the arrow at sp, turning the head o? the u f towa rd theside on which it is ausinsr the machine moinen-` a curved flight; thecentri?-`v devcioue'd hv curvilinear movemos the tendency to lateral andand vat the same time nt. due to the shiftingr rd. that to le of theitil' aju/a y 'machine'. i; 'L H and brings i cmd perhaig tien. 5x9 thatsmaad iti.

This automatic righting action resembles that of a moving bicycle in itsinstantaneous restoration ofthe machine to its normal level whenever itis momentarily deflected or inclined.

In the preferred construction illustrated in Figs. 3, 4 and 5, thesupporting planes are arched, each wing being composed of up wardlyextending sections P, downwardly extending sections P2, and upturnedtips P3. This arched construction produces regions of high air densitynear the crown of the arch, lends itself readily to stiffening by meansof truss rods or tie-wires, and reduces the liability to side-sliding.The. behavior of gliding models built on this plan shows that wheneverone wing is depressed the machine automatically banks itself andresumeshorizontal position. Y v

It will now he clear that a machine of the character described may besteered without any vertical rudder. by means of horizontal rudders,such as P4 (Fig. 4) which are hinged to turn on axis transverse to thefore-and-aft center line of the machine. or b v Wing-warping devices. Byincludingr horizontal rudders or warping wings, the machine may beinclined to one side or the other, and then the tail, acting as abovedescribed. will swing the machine in a curve with its center on thedepressed side.

A continuously self-sustaining machine 'embodying the principles aboveexplained,-

is suggested b v Figs. 3, 4 and 5. The weight of the entire bodvstructure, including engine E, housing H, propellers B. frame F andpoutoons C is so distributed that the center' of gravity is located atcg (Fig. The aviators seat A is so placed that his weight shall notappreciahly shift the center of gravity ot the whole. The wings arcarcl'ied. and comprise planes P', P2 and P3', and horizontal rudders P*which arehinged on the transverse line 7), The tail T is pivoted at t.and' controlled by the aviator through connections which include togglesT. and stops S, S limit the extremes of inclination of the tail T. Avertical rudder R may be provided7 but is not essential; it may well beset at a slight angle to compensate for dritt due to propeller torque,if but one propeller is employed. The machine shown is adapted to risefrom and alight on water; the usual landing wheels and a suitablechassis may he substituted for 1? the pontoons C. i

In the preferred construction illustratedjin Figs. 3. 4 and 5, thepropeller shaft, and therefore the line of forward draft. is parallel tothe supporting planes.Y and these planes are made. as straight, fromfront to rear, as the necessities of construction will allow. The undersurfaces of the supportas shown, should be fiat on its upper side, andhave its leading edge close to the trailing edge of the supportingplanes.

As was demonstrated at a relatively early date by the performance ofLilienthal and Pilcher (among others) supporting surfaces arched fromfront to rca r. while affording increased lift, naturally tended to makethe machine move in a curve coincident with the curvatuie of thesupporting surfaces, and therefore to plunge downward The center ofgravity, in such machines, neces sarily had to be located in the rear ofthe actual center of upward pressure, and with the weight so disposed, atail plane, set at or moved to, a negative angle, sufiiced or assistedto prevent the machine from diving in response to the tendency of thecurved wing surfaces to follow the path of their own curvature, If thecenter of .grav ity in a machinehaving a curved supporting surface, beplaced forward, or even coincident with, the center of supporting pres--sure, the diving tendency will be too strongr to be overcome by a tailplane set at a nega,- tive angle less than that which will unduly retardthe glidingunovemcnt.

The stops S, S are so fixed that the upper stop prevents the tail planefrom reaching a position parallel with the supporting planes, and sothat the lower stop will hx the tail plane at the extreme inclinationsuited to a slow downward glide. lt is important to so limit theadjustment of thc tail plane that under no conditions can thc balancingdownward pressure of air onits upper surface be lost,

lt is well known that the center of supporting pressure varies itsposition with the angle of positive inclination, and with speed advance,so that the positions of center of gravity and center of pressure. shownin the drawings are intended solely as diagrammatic indications. Theconstructor will take into account the known data with .respect tochanges of center of pressure and proportion the machine so that thecenter of gravity will be forward of the center of pressure under anyconditions.

\Vhat we claim and desire to secure by Letters Patent is:

l. In an aeroplane, the combination of` supporting planes. a body, and atail plane, all so coordinated that the center of gra vity of thestructure is located forward of thc center of pressure of the supportingplanes. and the tail plane presents its upper surface at an angle tonormally exert during flight a downward air pressure pull in oppositionto the downward pull of the weight of the structure, referred to thecenter of pressure as a fulcrum, and a support for the aviatorsubstantially coincident with the center of gravity of the structure.

2. In an aeroplane, the combination of laterally arched supportingplanes, a body, and a tail plane, all so coordinated that the center ofgravity of the structure is located forward of the center of pressure oftheV arched supporting planes, and the tail plane presents its uppersurface at an angle to normally exert during flight a downward airpressure pull in opposition to the downward pull of the weight of thestructure, referred to the center of pressure as a fulcrum, and asupport for the aviator substantially coincident with the center ofgravity of the structure.

3. In an aeroplane, the combination or supporting planes, a body, and atail plane, all so coordinated that the center of gravity of thestructure is located forward of the center of pressure of the supportingplanes, and the tail plane presents its upper surface at an angle tonormally exert during flight a downward air pressure pull in oppositionto the downward pull of the weight of the structure, referred to thecenter of pressure as a fulcrum. means such as horizontal rudders forlaterally inclining the aeroplane from its normal horizontal position.and a support for the aviator substantially coincident with the centerof gravity of the structure. i

4. In an aeroplane, the combination of laterally arched supportingplanes. a body, and a tail plane, all so coordinated that the center ofgravity of the structure is located forward of the center of pressure ofthe arched supporting planes, and the tail presents its upper surface atan angle to normally exert during flight a downward air pressure pull inopposition to the downward pull of the weight of the structure, referredto the center of pressure as a fulcrunx. means such as horizontalrudders, for laterally inclining the aeroplane from its normalhorizontal positiongand-a vfupport for the aviator substantiallycoincident with the center of gravity of the structure.

5. In an ae1oplane,the combination of supporting planes substantiallyflat in fore-andaft section. abody. and a tail plane, all so coordinatedthat the center of gravity of the structure is located forward ofthecenter' of pressure of the supporting planes, and the tail planepresents its upper surface at an angle to normally exert a downward pullin opposition to the downward pull of the weight of the structure.referred to the center of pressure as a fulcrum, and a snpport for theaviator substantially coincident vwith the center of gravity of thestructure.

supporting planes, and the tail plane pre- -ents it-` upper surlaee atan angle to norina'ljv exert a downward pull in opposition to thedov-toward pull of the weight of the -tr|uture. referred to tlnl eenterof pressure as a filierum. and a support 'for the aviator y ytantialheoineident with the renter of grafitv of the strut-ture.

T. ln an zn'roplane. the r'oinbination of supporting' planes. a bod'v.and a tail plane. all so coordinated that the center of gravity of thestructure is loeated forward ot' the renter of pressure' of thesupporting planes. and the tail plane presents its upper surfaee at anangle to normallyY exert during flight a downward air pressure pull inop position to the downward pull of the weight of the strneture,referred to the Center of pressure as`V a fulorum. a propeller havingits line of draft substantially parallel to the foreainl-aft seetion ofthe supporting planes. and a support for the aviator sul)- stantiallyeoineident with the renter oll gravit'r of the structure.

H. ln an aeroplane. the Combination of laterall)Y arehed supportingplanes. a body. and a tail plane. all .so coordinated that the renter ofgraviti' of the strut-tare is: lorated forward of the center of pressure'.f the arehed supporting planes. and the tail plane presents its uppersurfaee at an angle to normallv exert during llight a downward airpressure pull in opposition to the downward pull of the weight of thestructure, referred to the renter of pressure as a fulerum. a propellerhaving its'line of 'draft substantially parallel to the fore-and-a.ftseetion of the supporting'planes. and a support for the aviatorsubstantially roineident with the renter of gravity of the struetare.

tl. ln au aeroplane. the eonlbination of supporting' planes. a body. anda tail plane. all so eoh'dinated that the eenter of gravit)v ol' thestruetnre is lot-ated forward of the renter ot the snpl'iorting planes.and the tail plane presents its upper surface at an angle to normallyexert during flight a downward air pressure pull in opposition to 'thedownward pull otI the weight of the strut-ture, referred to the renterot' pressure as. a fulrrum. means suoli as horizontal rudders, forlaterall)Y inelining the aeroplane from its normal horizontal position,a propeller having its line of draft Substantially parallel to thefore-:unl-aft section of the supporting planes. and a support for theaviator .suhstantiallv eoineident with the renter of gravity ol' thestructure.

lu. ln an aeroplane. the eoinbination of laterall)Y arched supportingplanes. a body, and a tail plane. all so eoirt'linated that the renterof gravity of the .strueture is located forward of the eenter ot'pressure of the arched supporting planes` and the tail presents itsupper surt'af-e at an angle to nor mallv exert during [light a downwardair pressure pull in opposition tothe downward pull of the weight ot'the strneture, referred to the eenter of pressure as a fulernln. meanssueh as horizontal rudders. for laterallv inelining the aeroplane fromits normal hori- Ynontal position, a propeller having its line of draftsubstantiall)v parallel to the foreand-aft section of the supportingplanes. and a support for the aviator .substantiallyv eoineident withthe renter of `gravitaY oll the structure.

11. ln an aeroplane. the combination of supporting planes substantiallytlat in foreand-aftI section. a hod'v. and a tail plane. all soCoordinated that the renter of gravitv of the structure is loratedforward ot' the eenter of pressure of the supporting planes. and thetail plane presents its upper surfaee at an angleI to normali)v exert adownward pull in opposition to the downward pull of the weight ofthestrutture. referred to the renter of pressule as a l'aluruna. apropeller having its line ol" draft .substantially-parallel to thefrae-andnft f-.eetion of the supporting` planes. and a support for theaviator' substantially mint-ident withtlueenter of gravit)7 of thestrutture.

12. ln laterall)rv arehed supporting planes substantiall'v l'lat infore-aml-aft seetion. a bodv.

and a tail plane. all so eoordinated that the renter of gravity of thestrueture is loeated forward of the center of pressure ol' the.supporting planes. and the tail plane prt sents its` upper surfaee at:an angle to nor mally exert a downward pull in opposition to thedownward pull of the weight of the strneture, referred to the renter ofpressure as a fulerum` a propeller having s line, of draft substantiallyparallel to the frreand-aft seetion of the supporting plains. and asupport for the aviator substantially coincident with the eenter ofgravity o't' the structure.

Signed b v us at Boston. Massaehusetts.

this 25th day7 of Ma)r 19,12..

RUSCOE I. TIMSUN.

GEORGE NORMAN 'Llltllll.

'itnesses ("nAnLias l). 'rjiomsnunr, Joshi-MINE ll. RYAN.

an aeroplane. the eombination ofV

